With marijuana becoming legal in some states, the use of this substance is obviously going to increase, which is bound to have an impact on how certain laws are enforced. The legalization of marijuana in Colorado and Washington has raised concerns over high driving and whether legalization will increase the number of stoned drivers. Also, there is the question of how police will now regulate driving while high and how officers will determine whether a driver is stoned or not. Since marijuana is no longer a prohibited substance, at least in a few states, driving under the influence of marijuana has to be regulated differently than it has been so far and a legal limit for marijuana intoxication will probably have to be determined.
While driving with a blood alcohol content (BAC) of .08% or higher is considered to be illegal according to current US DUI laws, there is no such limit for marijuana. This is where the questions of how marijuana affects a person’s driving abilities and whether the accident risk for drivers under the influence of marijuana is higher than for drunk drivers come in. Many studies have been conducted to test the effects of marijuana on drivers, and most of them conclude that, while it impairs certain skills that are important for driving performance, it does not reduce driving abilities as much as alcohol does.
Marijuana use results in slower reaction times, and it affects judgment and coordination. It also impacts short-term memory and some other cognitive functions, but overall, it doesn’t prevent a person from performing basic driving tasks. Studies show that when under the influence of marijuana, drivers tend to drive slower and pay more attention to traffic signs, as they are aware of their impairment and try to compensate by driving more carefully – which is very different from what drunk drivers do. Drivers with high blood alcohol content may drive fast, often exceeding speed limits; they drive more aggressively and recklessly, disregarding traffic laws – and many of them feel that drinking alcohol does not reduce their driving abilities.
These findings should be taken into consideration by those intending to enforce legal limits for marijuana intoxication. While some Colorado lawmakers are asking for a zero-tolerance policy on driving under the influence of marijuana, others are suggesting that a legal limit of 5 nanograms should be put in place. This would mean that drivers with less than 5 nanograms of THC per millimeter of blood in their bloodstream will not be convicted of driving under the influence of marijuana. This kind of limit has already been set in Washington State, and Nevada has the limit at 2 nanograms of THC per millimeter of blood.
In addition to the issue of setting a limit for marijuana intoxication, there is the issue of how law enforcement will identify stoned drivers. The breathalyser test that is used to determine a driver’s blood alcohol content can’t determine the exact amount of marijuana in a person’s bloodstream. Potential alternatives include teaching officers how to recognize symptoms of marijuana impairment, as well as testing a driver’s saliva.